Parallax barrier systems that allow a viewer to see a stereoscopic image without the use of special glasses are known. A parallax barrier based stereoscopic display device includes, for example, a display panel and a switch liquid crystal panel. The display panel displays stereoscopic images. The switch liquid crystal panel can implement a parallax barrier. The parallax barrier includes apertures that pass light and light-shielding portions that block light. In the parallax barrier, apertures and light-shielding portions are arranged alternatingly.
In the case of a parallax barrier based stereoscopic display device with two viewpoints, the viewer must be located at the optimum viewing position to see stereoscopic images displayed on the display panel; if the viewer is not located at the optimum viewing position when viewing images, moire occurs on the screen, caused by light-shielding areas of the display panel (for example, the black matrix), preventing good display quality.
JP 2004-157411 A discloses a video display device that reduces moire. This video display device includes apertures for separating different videos displayed on the screen. The outlines of the apertures include transverse line portions that are non-parallel to the outlines of the pixels.
However, in the video display device of the above publication, the light-shielding portions (and apertures) are not continuous in a vertical direction of the screen. As such, when the viewer nods his head vertically (i.e. moves his gaze) while seeing stereoscopic video, crosstalk may easily occur, which means that the area where a viewer can experience good stereoscopy (hereinafter referred to as degree of freedom) is small.